C++ Program for a wall-clock implementing class, constructor and member functions.

Define a class with necessary constructor & member functions. Derive wall-clock from class adding necessary attributes. Create two objects of wall_clock clasess with all initial state to 0 or NULL.

Algorithm:

1. start of program
2. create a class (clock) with necessary constructor and member functions
   1. clock()                      //constructor to initialize the time to 0:0:0
   2. getdata()                //ask for time in the format of hr:min:sec
   3. add(clock t)          //for adding time
   4. display()                 //display the time
3. create a derived class (wall_clock) inherited publicly from base class clock
4. create instance(object) of the derived class and access the base functions to add two times (t1.add(t2));and
5. display the final time
6. end of program

Source Code:

#include<iostream.h>

#include<conio.h>

class clock

{

protected:

int hr,min,sec;

public:

clock()

{ hr=0;

min=0;

sec=0;

}

void getdata(int h,int m,int s)

{ hr=h;

min=m;

sec=s;

}

void add(clock t)

{

sec+=t.sec;

if(sec>=60){

sec%=60;

min++;}

min+=t.min;

if(min>=60)

{ min%=60;

hr++;

}

hr+=t.hr;

}

void display()

{ cout<<hr<<":"<<min<<":"<<sec;

}

};

class wall_clock:public clock

{

};

void main()

{ clrscr();

wall_clock t1,t2;

t1.getdata(1,1,1);

t2.getdata(2,59,59);

cout<<endl<<"time1=";

t1.display();

cout<<endl<<"time2=";

t2.display();

t1.add(t2);

cout<<endl<<"add=";

t1.display();

getch();

}

 Output: